The ability to time underlies adaptive behavior. Skilled motor sequences are carefully timed. Decisions about whether or not to take an action depend on knowledge of when they are appropriate. Memories for how long actions usually take underlies most ordinary activity such as planning a day or knowing how long it takes to cross a street. This learning of time is largely automatic is a foundation of behavioral organization. Disordered timing and distorted anticipation are associated with a number of psychiatric disorders including attention deficit hyperactivity disorder, schizophrenia and depression. The purpose of this grant is to understand how times are learned, remembered and used to guide behavior. PUBLIC HEALTH RELEVANCE: There are deficits in timing and anticipation in many behavior disorders. Depression, schizophrenia and attention-deficit-hyperactivity disorder are all associated with distortions in time perception and changes in the capacity to anticipate predictable events. Drug-taking and other habitual high-risk behaviors are associated with diminished capacity to anticipate long-term consequences. An understanding of the mechanisms of anticipatory learning will lead to more widespread and effective behavioral and biological treatments.